The cavernous structure of the skull is extremely intricate and detailed. All the bones are delicately sutured together in very specific and accurate way. This section of anatomical genius is exactly like a difficult puzzle, where every bone is formed to make a single puzzle piece, which cannot fit anywhere else but where it was designed to. This article aims to provide the reader with an insight to how these puzzle pieces should be placed. Each bone will be mentioned, it will be clarified whether or not it is a paired or single bone and finally a list of surrounding bones that directly articulate with the bone in question will be provided.
The bones below are not listed in any particular order:
- the frontal bone is a single bone that articulates with the parietal bone, the sphenoid bone, the zygomatic bone, the maxilla, the ethmoid bone, the nasal bone and the lacrimal bone.
- the parietal bone is a paired bone and these two pieces are symmetrically bilateral. They anchor with the frontal bone, with each other (the opposite parietal bone), the temporal bone, the occipital bone and the sphenoid bone.
- the temporal bone is also a paired bone that is linked to the parietal bone, the occipital bone, the sphenoid bone, the zygomatic bone and the mandible.
- the occipital bone is a single bone that is unique because it is the only cranial bone that articulates with both cranial bones and vertebral bones. Apart from the first cervical vertebrae (C1), otherwise known as the atlas, the occipital bone joins up with the parietal bone, the temporal bone and the sphenoid bone.
- the sphenoid bone is also a single bone that comes into contact with the frontal bone, the parietal bone, the temporal bone, the occipital bone, the zygomatic bone, the maxilla, the ethmoid bone, the palatine bone and the vomer.
- the zygomatic bone is bilaterally symmetrical and therefore paired. It articulates with the frontal bone, the temporal bone and the maxilla.
- the maxilla is a paired bone. This may seem surprising, since it looks like a single bone mass, but upon closer inspection, there is a very thin midline suture. It articulates with the frontal bone, the zygomatic bone, the ethmoid bone, the palatine bone, the vomer, the nasal bone, the lacrimal bone, the inferior nasal concha, and the adjacent fused maxilla. Sometimes it also articulates with the orbital surface or lateral pterygoid plate of the sphenoid bone. Out of all the cranial bones the maxilla has the most articulations, nine or ten.
- the ethmoid bone is a single bone whose neighbours include the frontal bone, the sphenoid bone, the maxilla, the palatine bone, the vomer, the nasal bone, the lacrimal bone and the inferior nasal concha.
- the palatine bone is a paired bone separated by the midline suture. Apart from being joined to its pair, the palatine bone articulates with the sphenoid bone, the maxilla, the ethmoid bone, the vomer and the inferior nasal concha.
- there is only one vomer and this bone is surrounded by the sphenoid bone, the maxilla, the ethmoid bone and the palatine bone.
- the pair of nasal bones link to each other and to the frontal bone and to the maxilla.
- the lacrimal bones do not link to one another, but to the frontal bone, the maxilla, the ethmoid bone and the inferior nasal concha.
- the inferior nasal concha also don’t link to one another. Their surrounding structures include the maxilla, the ethmoid bone, the palatine bone and the lacrimal bone.
- the final cranial bone is the mandible. This is one big bone and it has the least articulations of all the cranial bones. Its single link is to the temporal bone.
Fractures of the cranial bones can occur in many different forms, depending on the circumstances of the injury. Clinically a fracture can be simple, which means without dislocation of the bones or an open wound, it can also be complicated, which is the next stage where there is dislocation and an open wound. The last type is known as a greenstick fracture. This occurs mostly in children who have more flexible bones. One side of the bone is simply distorted, while the other side is fractured and sometimes dislocated. A fracture can be complete, which is when is spans the whole width or length of the bone, or incomplete, where it partially transcends the thickness of the bone.
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